Automatic fire extinguisher



July 30, 1957 c. c. MCKISSICK AUTOMATIC FIRE EXTINGUISHER Fiied July 17, 1956 IN V EN TOR. 0/4 [155 6. m /r/ss/cw BY I Wm; WM ATTOZ/VE Y5 United btates Patent G AUTGMAT 1C FEE EXTENGUISHER Charles C. McKissick, El Cerrito, Calif.

Appiication July 17, 1956, Serial No. 598,446

Claims. (Cl. 169-4 5) This invention relates to fire extinguishers, and more particularly has reference to a device of this nature intended particularly for installation on motor cars, airplanes, or any other vehicles where automatic controls can advantageously be employed. The invention further is adapted for use in stationary installations, if desired.

In many instances, a vehicle that becomes involved in a collision suffers gasoline tank damage. This results in spillage of fuel, in turn creating a serious fire hazard which many times causes fires almost immediately after the collision occurs.

The main object of the invention, therefore, is to provide an extinguisher that will be triggered automatically on impact, to release itssolution directly in the area in which spillage most usually occurs. To this end, the invention may be briefly described as including a reservoir for a fire extinguishing solution, in which the solution is kept under or may be subjected to high pressure; an outlet cylinder having discharge ports normally closed by an annular gasket; a cup-like piston normally extending through the gasket to hold the same in sealing position; and a rod extending from the piston, to permit manual movement of the piston out of the gasket, the piston and rod also being adapted to automatically shift to a gasketreleasing position responsive to heavy impact such as occurs in a collision. Following extraction of the piston from the gasket, the pressure of the reservoir contents acts to shift the gasket away from the discharge ports for automatic release of the contents in the area in which a fire has started or is prone to occur. The device is so arranged as to permit opposed mounting of similar extinguishers, with the rods thereof extending through a guide means common to both of them, if desired. In a modified embodiment, the device includes a frangible cartridge containing a gas under pressure which is adapted to force the solution under pressure from the reservoir, said cartridge being connected with the piston so as to be ruptured simultaneously with movement of the piston to its gasket-releasing position.

Among objects of importance in the invention are the following:

First, to provide an extinguishing device as stated that will be automatically operable to release extinguishing fluids or gases on impact;

Second, to provide a novel sealing means deriving from the particular formation and relative arrangement of the outlet cylinder, gasket, and piston;

Third, to provide novel means for simultaneously rupturing a cartridge containing a gaseous propellant, and moving the piston to its releasing position;

Fourth, to facilitate installation of the extinguisher on conventional motor vehicles and other structures; and

Fifth, to permit the extinguisher to be operated either manually, automatically, or by electrically actuated means.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

2,800,966 Patented July 30, 1957 "ice Figure 1 is a fragmentary top plan view of a vehicle frame in which a pair of the extinguishers is mounted;

Figure 2 is an enlarged, fragmentary longitudinal section through one of the extinguishers with the gasket in sealing position;

Figure 3 is a transverse section on line 33- 3 of Figure 2;

Figure 4 is a view like Figure 2 in which the piston is in releasing position;

Figure 5 is a view like Figure 2 showing a modified form; and

Figure 6 is a view like Figure 5 with the piston in releasing position.

A conventional motor vehicle generally designated 10, constituting merely one of many structures on which the device can be mounted, has side frame members 12, a rear frame member 14, and a fuel tank 15 extending transversely of the frame slightly forwardly of the rear frame member 14.

In the space between tank 15 and rear frame member 14, a pair of the fire extinguishers 16, constituting the invention, are mounted in opposed relation, each being secured at its outer end to an adjacent side frame member 12, by a suitable bracket 17.

Each extinguisher 16 includes a tank or reservoir 18 of cylindrical formation, having a dome-shaped head or end wall 29 centrally formed with a threaded opening surrounded by an inwardly directed flange 22. Within the dome-shaped head 20 an outlet cylinder 24 is mounted, extending axially of and within reservoir 18 and formed at its outer end with external threads 25 engaging the threads of the reservoir opening. An outwardly directed end flange 26, formed on cylinder 24, bears against the head 2% to limit inward threading of the outlet cylinder.

Intermediate its ends, the outlet cylinder 24 is integrally formed with a circumferentially extending outwardly pressed rib 23 of V-shaped cross section defining in the cylinder an inwardly facing, continuous, circumferential groove 29 of corresponding cross section.

At its inner end, cylinder 24 is integrally formed with an inner end wall 30.

In one wall of the groove 29 there is formed a circumferential series of uniformly spaced discharge ports 32, providing outlets for the contents of reservoir 18. Said ports are normally closed by an annular gasket 34 of resiliently compressible material such as rubber.

A releasing piston 36 is of a cup-shape, and opens toward the end wall 36 in its closed end. The piston is formed with an annular series of apertures 38, and secured to the center of the closed end of the releasing piston is an elongated, straight rod of brass or other non-corrosive metal. Rod 40, adjacent the piston, extends through a center opening of a generally conically shaped, resiliently compressible sealing plate 42 formed at its periphery with a frusto-conically shaped shoulder 44 (Figure 4) normally bearing against a compiementarily formed internal shoulder 46 formed upon the outer, flanged end of the outlet cylinder.

Reservoir i8 is adapted to hold a quantity of a fire extinguishing solution. This may be a wholly conventional solution of the type adapted to be confined under high pressure, such as one of the well-known foaming solutions.

In use, the device is mounted as shown in Figure 1, and two of the extinguishers can be disposed in opposed relation, with the piston rods 46 extending in parallel relation and overlapping in the space between the reservoir 18. The overlapping ends of the rods are slidably engaged in parallel bores formed in a sleeve 48 located midway between the reservoirs. Alternatively, sleeve 48 could be fixedly connected to one of the rods 40 with the other rod sliding in the sleeve.

The extinguishers are so located that on impact, a force is exerted on one or both of the devices, sufficient to shift piston 36 from its Figure 2 to its Figure 4 position. When in its normal, Figure 2 position,,the piston spreads the gasket 34, radially expanding the same'to Compress the gasket into intimate, sealing relation to the discharge ports .32, within groove29; When, however, impact occurs, the movement of the piston from its .Figure 2 to its, Figure 4 position will cause'the marginal portion of sealing plate or ring 42 to be flexed in the direction of the piston, to disengage the shoulders 44, 46. The piston, moving to its'Figure 4 position; now engages shoulder 46, with ports or apertures 38 providing communication between the interior of outlet cylinder 24 and .atmosphere. a

V as to impart axial movement of the piston 36 from its Figure 2 to its Figure 4 positions.

In Figures and 6, there. is shown a modified construction. In this form the invention is identical to'the first form except for the fact that the side wall of the outlet cylinder is extended axially within the tank beyond the inner end wall 30 to provide a tubular extension 50 on the cylinder separated from the interior of the cylinder by the end Wall 30. Within extension 50 there is a capsule or cartridge 52 containing a gaseous propellant, said cartridge having at one end a frangible head 54 secured to an extension rod 56 slidably mounted in thewall 30. Packing gland 57 surrounds the end wall opening, and within cylinder 24 the extension 56 extends into and is secured to the closed end of piston 36.

Adjacent end wall 30, the tubular extension 50 is formed with a circumferential series of uniformly spaced orifices 58 shapedas slots extending longitudinally of the tubular extension. Adjacent the orifices 58 there is provided an internal shoulder 60 in the extension, forming an abutment for the cartridge 52.

The sealing disc 42 can be employed in this form of the invention,'but alternatively, there can be provided a sealing ring 42a differing from ring 42 in that it has a peripheral groove 44:: shaped to define a shoulder bearing against the shoulder 46. v

The sealing ring 42a could if. desired be used in the 'form of the invention shown in Figure 2.-

In the modified construction, on impact tending to cause movement of piston 36 to its Figure 6, releasing position, conjoint movement will be imparted to the extension rod 56, causing it to break the head 54 of the cartridge, thus opening the cartridge to release the propellant.

Said propellant as shown in Figure 6 moves outwardly through orifices 58 so as to be intermixed with the tank contents, combining with said contents in forming-a wire extinguishing fluid that will be forced under pressure, due to the nature of the propellant, into the outlet cyl- V inder 24 through the ports 34, to be thereafter directed valve, however, must not be so readily achieved as to cause the device to be triggered on impact less than that which would occur in a collision, particularly a rear end collision.

Further, the device is designed so that it could be manually operated, or operated by some type of electrical device which could, for example, be controlled from the instrument panel. The device need not be necessarily mounted behind the gas tanks as shown but could be located in the motor compartment so that the extinguisher can be opened by a pull or pressure on the triggering rod.

The tank, controls, and valve assembly should be Weatherproofed, and are designed for endurance and full workability in all types of weather, as for example, in weather conditions that would normally tend to coat the device with mud or ice.

The unit can be used singly rather than doubly as shown in Figure 1. It may be noted that the outer seal 42 or 42a. is so designed as to insure that the inner working parts are always kept clean and in working condition. Further, the outer seal provides an auxiliary sealing means cooperating with the gasket in preventing leakage of the reservoir or tank contents.

Obviously, any materials employed can be varied if desired, so long as they are resistant to corrosion and are adapted to discharge their assigned functions. 7

It is believed apparent that the invention is .not nec essarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope'of the appended claims.

What is claimed is:

l. A fire extinguisher comprising: a reservoir for an extinguishing fluid; an .outlet cylinder therein opening to atmosphere and formed with an inwardly facing circumferential groove, said cylinder having in the wall of said groove a port providing communication between the interiors of the outlet cylinder and the reservoir; an annular, resiliently compressible gasket normally seating in the groove to close said port; and a piston inthe cylinder normally extending through the gasket and radially expanding the same into the groove to a port-sealing position, said piston being shiftable in the cylinder to a position freeing the gasket for movement out of the groove to a port-exposition position.

2. A fire extinguisher comprising: a reservoir foran extinguishing fluid; an outlet cylinder therein opening at one end; to atmosphere and formed intermediate its ends with an inwardly facing circumferential groove, said cylinder having in the wall of said groove a port providing communication between the interiors of the outlet cylinder and the reservoir, the cylinder having an internal shoulder at said end thereof; an annular, resiliently compressible gasket normallyseating in the groove to close:said port;

a piston in the cylinder normally extending through the gasket and radially expanding the same into the groove to a port-sealing position, said piston being shiftable in the cylinder to a position freeing the gasket for movement out of the groove to a port-exposing position; a rod extending from the piston out of the reservoir; and a flexible sealing ring on the rod normally bearing against i one end to atmosphere and formed intermediate its ends with an inwardly facing circumferential groove,'said cylinder having in the Wall of said groove a port providing communication between the interiors of the outlet cylinder and the reservoir, the cylinder having an internal shoulder at said end thereof; an annular, resiliently compressible gasket normally seating in the groove to close said port; a piston in the cylinder normally extending through the gasket and radially expanding the same into the groove to a port-sealing position, said piston being shiftable in the cylinder to a position freeing the gasket for movement out of the groove to a port-exposing position; a rod extending from the piston out of the reservoir; and a flexible sealing ring on the rod normally hearing against the shoulder, said sealing ring being made fast to the rod and the rod being rigidly connected to the sealing ring, for flexure of the sealing ring with the shoulder on movement of the piston to its gasket-freeing position, said piston, when moved to its gasket-freeing position, engaging against said shoulder, the piston being formed with a plurality of apertures located inwardly of the shoulder, providing outlets to atmosphere for the extinguishing fluid.

4. A fire extinguisher comprising: a reservoir for an extinguishing fluid; an outlet cylinder therein opening to atmosphere and having a port providing communication between the interiors of the outlet cylinder and the reservoir; a gasket normally closing said port; a piston in the cylinder normally engaged in the gasket and holding the gasket in its port-sealing position, said piston being shiftable in the cylinder to a position freeing the gasket for movement to a port-exposing position; a rod rigid with the piston and extending within the reservoir; a cartridge engaged in the reservoir adapted to contain a gaseous propellant; and a frangible head on the cartridge secured to said rod, for opening the cartridge into communication with the interior of the reservoir responsive to conjoint movement of the rod and piston resulting from shifting of the piston to its gasket-freeing position.

5. A fire extinguisher comprising: a reservoir for an extinguishing fluid; an outlet cylinder therein opening to atmosphere and having a port providing communication between the interiors of the outlet cylinder and the reservoir; a gasket normally closing said port; a piston in the cylinder normally engaged in the gasket and holding the gasket in its port-sealing position, said piston being shiftable in the cylinder to a position freeing the gasket for movement to a port-exposing position; a rod rigid with the piston and extending Within the reservoir; a cartridge engaged in the reservoir adapted to contain a gaseous propellant; a frangible head on the cartridge secured to said rod, for opening the cartridge into communication With the interior of the reservoir responsive to conjoint movement of the rod and piston resulting from shifting of the piston to its gasket-freeing position; a tubular extension formed upon the cylinder within the reservoir, the cylinder including an inner end wall providing a partition between the interiors of the extension and of the cylinder, said extension being formed with orifices communicating with the interior of the reservoir; and a shoulder internally formed upon the extension and constituting an abutment engaging the cartridge, whereby, on conjoint movement of the piston and rod, said head of the cartridge will be pulled oi? the body of the cartridge with the body of the cartridge engaged against said shoulder, to free the propellant for movement out of the extension through the orifices into the reservoir, thus to intermix the propellant and the reservoir contents for flow under pressure through the port of the cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 2,115,371 Mossberg Apr. 26, 1938 2,166,277 Adams July 8, 1939 2,730,179 Ferguson Jan. 10, 1956 

